555

What would you like to do with the number 555? Here are some quick facts and a few practice prompts you can use for exams.

Quick facts

• Prime factorization: 555 = 3 × 5 × 37
• Positive divisors: 1, 3, 5, 15, 37, 111, 185, 555
• Sum of divisors (including 555): 912
• Sum of proper divisors: 912 − 555 = 357
• Classification: 555 is a deficient number (sum of proper divisors < number)
• In other bases: binary 111? No—555 = 1000101011₂; hex 0x22B
• Roman numeral: DLV
• Digit facts: sum of digits = 5+5+5 = 15; product of digits = 5×5×5 = 125

Practice prompts (with answers)

1. List all divisors of 555.
   • Answer: 1, 3, 5, 15, 37, 111, 185, 555
2. Compute the sum of divisors function σ(555).
   • Answer: 912
3. Is 555 a deficient, perfect, or abundant number?
   • Answer: Deficient
4. Convert 555 to binary and hexadecimal.
   • Binary: 1000101011₂
   • Hexadecimal: 0x22B
5. Express 555 as a product of primes and confirm the factorization.
   • 555 = 3 × 5 × 37 (each factor is prime)

If you’re studying a specific topic (e.g., number theory, base conversions, divisor functions), tell me and I’ll tailor more problems or explanations.